The standard model of particle physics describes the vast majority of experiments and observations involving elementary particles. Any deviation from its predictions would be a sign of new, ...fundamental physics. One long-standing discrepancy concerns the anomalous magnetic moment of the muon, a measure of the magnetic field surrounding that particle. Standard-model predictions
exhibit disagreement with measurements
that is tightly scattered around 3.7 standard deviations. Today, theoretical and measurement errors are comparable; however, ongoing and planned experiments aim to reduce the measurement error by a factor of four. Theoretically, the dominant source of error is the leading-order hadronic vacuum polarization (LO-HVP) contribution. For the upcoming measurements, it is essential to evaluate the prediction for this contribution with independent methods and to reduce its uncertainties. The most precise, model-independent determinations so far rely on dispersive techniques, combined with measurements of the cross-section of electron-positron annihilation into hadrons
. To eliminate our reliance on these experiments, here we use ab initio quantum chromodynamics (QCD) and quantum electrodynamics simulations to compute the LO-HVP contribution. We reach sufficient precision to discriminate between the measurement of the anomalous magnetic moment of the muon and the predictions of dispersive methods. Our result favours the experimentally measured value over those obtained using the dispersion relation. Moreover, the methods used and developed in this work will enable further increased precision as more powerful computers become available.
We compute the leading, strong-interaction contribution to the anomalous magnetic moment of the electron, muon, and tau using lattice quantum chromodynamics (QCD) simulations. Calculations include ...the effects of u, d, s, and c quarks and are performed directly at the physical values of the quark masses and in volumes of linear extent larger than 6 fm. All connected and disconnected Wick contractions are calculated. Continuum limits are carried out using six lattice spacings. We obtain a_{e}^{LO-HVP}=189.3(2.6)(5.6)×10^{-14}, a_{μ}^{LO-HVP}=711.1(7.5)(17.4)×10^{-10} and a_{τ}^{LO-HVP}=341.0(0.8)(3.2)×10^{-8}, where the first error is statistical and the second is systematic.
We compute the slope and curvature, at vanishing four-momentum transfer squared, of the leading order hadronic vacuum polarization function, using lattice quantum chromodynamics. Calculations are ...performed with 2+1+1 flavors of staggered fermions directly at the physical values of the quark masses and in volumes of linear extent larger than 6 fm. The continuum limit is carried out using six different lattice spacings. All connected and disconnected contributions are calculated, up to and including those of the charm.
The existence and stability of atoms rely on the fact that neutrons are more massive than protons. The measured mass difference is only 0.14% of the average of the two masses. A slightly smaller or ...larger value would have led to a dramatically different universe. Here, we show that this difference results from the competition between electromagnetic and mass isospin breaking effects. We performed lattice quantum-chromodynamics and quantum-electrodynamics computations with four nondegenerate Wilson fermion flavors and computed the neutron-proton mass-splitting with an accuracy of 300 kilo–electron volts, which is greater than 0 by 5 standard deviations. We also determine the splittings in the Σ, Ξ, D, and Ξcc isospin multiplets, exceeding in some cases the precision of experimental measurements.
Abstract
STUDY QUESTION
What is the global variability in recurrent implantation failure (RIF) definition, investigation and therapy, currently offered to patients undergoing IVF?
SUMAMRY ANSWER
...Definitions, diagnostic investigations and treatments offered to RIF patients differ widely amongst assisted reproduction healthcare professionals and clinical guidelines on RIF are urgently needed.
WHAT IS KNOWN ALREADY
RIF affects around 10% of patients undergoing IVF worldwide. There is no consensus on the definition of RIF, its diagnostic investigations or the therapeutic options, which leads to inconsistencies in clinical practice.
STUDY DESIGN, SIZE, DURATION
A cross-sectional study of clinicians and embryologists was conducted between May and June 2020. The survey included 43 questions aimed at understanding participants’ background and their current practice with regards to defining, investigating and managing RIF. The questions were designed by the European Society of Human Reproduction and Embryology (ESHRE) Special Interest Group (SIG) on implantation and early pregnancy following three consensus meetings.
PARTICIPANTS/MATERIALS, SETTING, METHODS
A total of 8579 ESHRE members from 6916 IVF centers were invited to participate using two global email calls based on their pre-specified interest in implantation and early pregnancy. SurveyMonkey and SPSS were used for data collection and analysis, respectively. Furthermore, differences were reported in the answers of European and non-European professionals, as well as between public and private settings and among clinicians clustered according to the average number of RIF patients treated per year.
MAIN RESULTS AND THE ROLE OF CHANCE
The final data set included 735 clinicians and 300 embryologist or IVF-biologists. The majority defines RIF based on the number of failed embryo transfers (ETs) with the most common threshold adopted being three ETs both fresh and frozen. More than two-thirds take lifestyle factors into account, mainly drugs, smoking and BMI. The highest consensus on which diagnostic investigations should be performed was reached for anatomical malformations and gynecological aspects focusing on hydrosalpinx, Asherman’s syndrome, endometrial thickness and endometriosis. Concerning treatment of RIF patients, the highest consensus was reached for preconceptional therapies, including BMI adjustment, smoking and endometritis followed by therapies during IVF procedures.
LIMITATIONS, REASONS FOR CAUTION
The response rate was relatively low, but comparable to other surveys.
WIDER IMPLICATIONS OF THE FINDINGS
A consensus on definition, diagnosis and treatment of RIF would help to reduce costly, time-consuming and poorly validated approaches.
STUDY FUNDING/COMPETING INTEREST(S)
No external funding was used. B.T. received support from Bayer for Clinical trials concerning endometriosis and Ferring for clinical trials concerning ovarian stimulation. She received reimbursement for travel expenses from Astropharm, Ferring. Dr Kade and is a shareholder of Reprognostics. She is a board member of the Austrian Society for Obstetrics and Gynecology (OEGGG), the associate head of the ‘Reproduktionsmedizinische Zentren Baden-Württemberg’ (RZBW), a member of guideline group of the German Society for Obstetrics and Gynecology (DGGG) and an editorial board member of the following journals: American Journal of Reproductive Immunology (AJRI), Archives of Gynecology and Obstetrics. All the other authors declare no conflict of interest.
TRIAL REGISTRATION NUMBER
N/A.
We present a QCD calculation of the u, d, and s scalar quark contents of nucleons based on 47 lattice ensembles with N_{f}=2+1 dynamical sea quarks, 5 lattice spacings down to 0.054 fm, lattice sizes ...up to 6 fm, and pion masses down to 120 MeV. Using the Feynman-Hellmann theorem, we obtain f_{ud}^{N}=0.0405(40)(35) and f_{s}^{N}=0.113(45)(40), which translates into σ_{πN}=38(3)(3) MeV, σ_{sN}=105(41)(37) MeV, and y_{N}=0.20(8)(8) for the sigma terms and the related ratio, where the first errors are statistical and the second errors are systematic. Using isospin relations, we also compute the individual up and down quark contents of the proton and neutron (results in the main text).
The optimal treatment of systemic sclerosis (SSc) is a challenge because the pathogenesis of SSc is unclear and it is an uncommon and clinically heterogeneous disease affecting multiple organ ...systems. The aim of the European League Against Rheumatism (EULAR) Scleroderma Trials and Research group (EUSTAR) was to develop evidence-based, consensus-derived recommendations for the treatment of SSc.
To obtain and maintain a high level of intrinsic quality and comparability of this approach, EULAR standard operating procedures were followed. The task force comprised 18 SSc experts from Europe, the USA and Japan, two SSc patients and three fellows for literature research. The preliminary set of research questions concerning SSc treatment was provided by 74 EUSTAR centres.
Based on discussion of the clinical research evidence from published literature, and combining this with current expert opinion and clinical experience, 14 recommendations for the treatment of SSc were formulated. The final set includes the following recommendations: three on SSc-related digital vasculopathy (Raynaud's phenomenon and ulcers); four on SSc-related pulmonary arterial hypertension; three on SSc-related gastrointestinal involvement; two on scleroderma renal crisis; one on SSc-related interstitial lung disease and one on skin involvement. Experts also formulated several questions for a future research agenda.
Evidence-based, consensus-derived recommendations are useful for rheumatologists to help guide treatment for patients with SSc. These recommendations may also help to define directions for future clinical research in SSc.
Introduction: Osteonecrosis of the jaw (ONJ) has been reported in patients treated with bisphosphonates. The incidence and risk factors associated with this disorder have not been clearly defined.
...Materials and Methods: We conducted a retrospective analysis of 4019 patients treated with intravenous bisphosphonates between 1996 and 2004. Our goals were to estimate the frequency, understand the clinical presentation, and identify risk factors associated with ONJ development.
Results: Sixteen of 1338 patients with breast cancer (1.2%) and 13 of 548 patients with multiple myeloma (2.4%) developed ONJ. The median dose and duration of treatment with pamidronate or zoledronic acid were significantly higher in patients with ONJ (p < 0.0001). Multivariate Cox proportional hazards regression analysis identified treatment with zoledronic acid (hazards ratio HR, 15.01; 95% CI: 2.41–93.48; p = 0.0037), treatment with pamidronate followed by zoledronic acid (HR, 4.00; 95% CI: 0.86–18.70; p = 0.078), and dental extractions (HR, 53.19; 95% CI: 18.20–155.46; p < 0.0001) as significant risks for ONJ in breast cancer. In multiple myeloma, dental extractions (HR, 9.78; 95% CI: 3.07–31.14; p = 0.0001) and osteoporosis (HR, 6.11; 95% CI: 1.56–23.98; p = 0.0095) were significant risk factors while controlling for bisphosphonate therapy. Thirteen of 29 patients were followed for a median of 17.1 mo (range, 7–67 mo); lesions healed in 3 patients during this period.
Conclusions: ONJ is an uncommon but long‐lasting disorder that occurs mainly in breast cancer and multiple myeloma patients treated with intravenous bisphosphonates. High cumulative doses of bisphosphonates, poor oral health, and dental extractions may be significant risk factors for ONJ development. ONJ resolved in 23% of patients with conservative therapy.
Abstract
STUDY QUESTION
What is the success rate in terms of ovarian activity (menstrual cycles) as well as pregnancy and delivery rates 1 year after orthotopic ovarian transplantations conducted in ...a three-country network?
SUMMARY ANSWER
In 49 women with a follow-up >1 year after transplantation, the ovaries were active in 67% of cases and the pregnancy and delivery rates were 33 and 25%, respectively.
WHAT IS KNOWN ALREADY
Cryopreservation of ovarian tissue in advance of cytotoxic therapies and later transplantation of the tissue is being performed increasingly often, and the total success rates in terms of pregnancy and delivery have been described in case series. However, published case series have not allowed either a more detailed analysis of patients with premature ovarian insufficiency (POI) or calculation of success rates based on the parameter ‘tissue activity’.
STUDY DESIGN, SIZE, DURATION
Retrospective analysis of 95 orthotopic transplantations in 74 patients who had been treated for cancer, performed in the FertiPROTEKT network from 2008 to June 2015. Of those 95 transplantations, a first subgroup (Subgroup 1) was defined for further analysis, including 49 women with a follow-up period >1 year after transplantation. Of those 49 women, a second subgroup (Subgroup 5) was further analysed, including 40 women who were transplanted for the first time and who were diagnosed with POI before transplantation.
PARTICIPANTS/MATERIALS, SETTING, METHODS
Transplantation was performed in 16 centres and data were transferred to the FertiPROTEKT registry. The transplantations were carried out after oncological treatment had been completed and after a remission period of at least 2 years. Tissue was transplanted orthotopically, either into or onto the residual ovaries or into a pelvic peritoneal pocket. The success rates were defined as tissue activity (menstrual cycles) after 1 year (primary outcome) and as pregnancies and deliveries achieved.
MAIN RESULTS AND THE ROLE OF CHANCE
The average age of all transplanted 74 women was 31 ± 5.9 years at the time of cryopreservation and 35 ± 5.2 at the time of transplantation. Twenty-one pregnancies and 17 deliveries were recorded. In Subgroup 1, tissue was cryopreserved at the age of 30 ± 5.6 and transplanted at 34 ± 4.9 years. Ovaries remained active 1 year after transplantation in 67% of cases (n = 33/49), the pregnancy rate was 33% (n = 16/49) and the delivery rate was 25% (n = 12/49). In Subgroup 5, tissue was cryopreserved at the age 30 ± 5.9 years and transplanted at 34 ± 5.2 years. Ovaries remained active 1 year after transplantation in 63% of cases (n = 25/40), the pregnancy rate was 28% (n = 11/40) and the delivery rate was 23% (n = 9/40). The success rates were age dependant with higher success in women who cryopreserved at a younger age. In Subgroup 5, tissue was exclusively transplanted into the ovary in 10% (n = 4/40) of women and into a peritoneal pocket in 75% (n = 30/40), resulting in spontaneous conceptions in 91% of patients (n = 10/11).
LIMITATIONS, REASONS FOR CAUTION
The data were drawn from a retrospective analysis. The cryopreservation and transplantation techniques used have changed during the study period. The tissue was stored in many tissue banks and many surgeons were involved, leading to heterogeneity of the procedures. However, this does reflect the realistic situation in many countries. Although patients with POI were evaluated before transplantation to allow specific analysis of the transplanted tissue itself, the possibility cannot be excluded that residual ovarian tissue was also reactivated.
WIDER IMPLICATIONS OF THE FINDINGS
This is the largest case series worldwide to date and it confirms that cryopreservation and transplantation of ovarian tissue can be a successful option for preserving fertility. Persistent tissue activity 12 months after transplantation suggests that the pregnancy and delivery rates may increase further in the future. As transplantation into the peritoneum results in a high success rate, this approach may be an alternative to transplantation into the ovary. However, in order to establish the best transplantation site, a randomized study is required.
STUDY FUNDING/COMPETING INTEREST
This study was in part funded from the Deutsche Forschungsgemeinschaft (# DI 1525) and the Wilhelm Sander Foundation (2012.127.1) and did not receive any funding from a commercial company. No competing interests.
TRIAL REGISTRATION NUMBER
None.
We compute the leading order hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon. The calculations are performed using four flavors of stout smeared staggered ...quarks, with quark masses at their physical values. The continuum limit is taken using six different lattice spacings ranging from 0.132 fm down to 0.064 fm. All strong isospin breaking and electromagnetic effects are accounted for to leading order. A controlled infinite volume limit is taken thanks to dedicated simulations performed in box sizes up to 11 fm. Putting all these ingredients together, we find (
g
µ
− 2)/2
LO−HVP
= 707.55.5 10
−10
, which has a total uncertainty of 0.8%. Compared to determinations based on the
e
+
e
−
→ hadrons cross section, our result significantly reduces the tension between the standard model prediction for the muon g − 2 and its experimental value.
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